The present invention relates generally to light emitting diode (LED) technology for lighting applications. It finds particular application in conjunction with spot module illumination applications and will be described with particular reference thereto. It will be appreciated, however, that the invention is also amenable to other like applications.
Current spot module lamp technology relies primarily on halogen-type lamps for miniature reflector (MR) and parabolic reflector (PAR) type lamp illumination. The use of halogen-type lamps for spot lighting, however, has some drawbacks. For example, excessive heating can limit the usage of these types of lamps for commercial and consumer applications. Existing LED solutions have utilized standard, off-the-shelf, epoxy encapsulated, through hole LED sources in the light source array. Such configurations severely limit the output intensity of the lamp. Therefore, the potential market penetration that may be realized. by LED technology is correspondingly limited.
Until now efforts in this technology area have been primarily focused on multi-color digital control of output light in order to provide xe2x80x9ccolor washxe2x80x9d capabilities in various styles of packages. LED-based lamps have been designed to mimic the MR lamp footprint. However, because the LEDs used to construct these lamps are not thermally conductive, the thermal resistivity of such lamps being about 300xc2x0 C./W, these LED lamps produce excessive heat. Therefore, thermal loading is a critical issue for conventional LED-based MR lamps.
One attempt at addressing the thermal issue has been to package surface mount devices onto a metal clad printed circuit board (PCB). However, this is merely a planar approach where the PCB is not directly integrated into a heat sink fixture included in the body of the lamp. Therefore, it has not been possible to incorporate high powered LED lamps into MR packages.
The present invention provides a new and improved apparatus and method which overcomes the above-referenced problems and others.
In accordance with one aspect of the present invention, a light module is provided. It includes a light emitting diode assembly defining a front side light emitting diode array and a rear side. The rear side is in thermal communication with a thermally conductive spreader, and a thermally conductive core is in thermal communication with the conductive spreader. The thermally conductive core includes an electrical conductor in operative communication with the front side light emitting diode array, and a plurality of appendages are disposed about the thermally conductive core such that they are in thermal communication with the conductive spreader.
In accordance with another aspect of the present invention, a light emitting diode assembly includes a light emitting face supported by a body through which electrical connection elements pass. The body includes a thermally conductive core in thermal communication with the light emitting face. The thermally conductive core includes the electrical connection elements in electrical communication with light emitting diodes in the light emitting face. A plurality of thermally conductive attachments surround the thermally conductive core, and they are in thermal communication with the light emitting diode assembly.
In accordance with yet another aspect of the present invention, a lamp is provided for use in connection with spot module platforms. The lamp includes a plurality of LEDs arranged in an LED assembly having opposing forward and rearward facing sides. The forward facing side selectively provides illumination from the LEDs when power is supplied thereto. A heat sink is in thermal communication with the rearward facing side of the LED assembly, and it is arranged to draw heat from the LEDs. Heat dissipating means is in thermal communication with the heat sink, and it dissipates heat from the heat sink via convection.
One advantage of the present invention is that it will reduce the thermal resistivity of LED-based spot modules in MR or PAR-type lamps or other novel lamp configurations.
Another advantage of the present invention is that it makes possible the use of high powered LEDs within spot modules in MR or PAR-type lamps or other novel lamp configurations. The number of LEDs in the array may vary as desired for particular applications.
Another advantage of the present invention is that it produces an LED-based lamp that substantially mimics the footprint of conventional MR lamps. The same approach can also be used in the case of PAR-type lamps.
Another advantage of the present invention is that it produces brightness levels that surpass conventional clip-on filtered MR lamps.
Another advantage of the present invention is that either primary or a combination of primary and secondary lens configurations may be used to focus the light output to provide angular output from the spot module ranging from 10xc2x0 to 65xc2x0 full-width-half-maximum.
Another advantage of the present invention is that the operating temperature of the LED is reduced, thus increasing the operating lifetime of the LED based lamp.
Still further advantages of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the preferred embodiments.